1. Swiftech MC462-A
2. Swiftech MC370-0A
3. Any other Swiftech waterblock/etc
Nothing touches Swiftech. MC462-A has not and (I don't believe) can be beaten. It is expensive, but you get what you pay for. And you've got a serious cooler that can air cool high voltage and high watt output instead of spending even more on a watercooling setup or peltiers, etc.
Don't buy in to the Glaciator, Gladiator, SK-6 hype. It's just hype, nothing more. The 462-A has been shown time and time again to stand in a league of its own.
FWIW, the 370-0A makes a fine "budget" (about $45-$50) solution. Gives up around 8C to the 462-A but still outperforms these phony devices everyone raves about.